Complications and surgical results of stone-directed antegrade pyelography compared to the retrograde pyelographic access method in percutaneous nephrolithotomy using ‘bull’s eye’ technique: A randomized clinical trial

Abstract

This study aimed to evaluate the differences in outcomes and complications in stone-directed antegrade pyelography using the ‘bull’s eye’ technique in patients with renal stones versus the conventional method of percutaneous nephrolithotomy (PCNL). Although conventional PCNL access using retrograde pyelography is useful, it is time-consuming and may cause postoperative discomfort. Herein, we report our experience in the application of this new technique. Between January 2017 and June 2018, 100 patients participated in this randomized clinical trial. Stone-directed antegrade pyelography using the ‘bull’s eye’ technique under fluoroscopic guidance was used for percutaneous access in the intervention group. The second group, consisting of those who had undergone conventional PCNL using retrograde pyelography and ‘bull’s eye’ technique in the same period, were considered as the controls. Pre- and postoperative laboratory examinations, surgical results and complications were recorded and compared between the two groups. A single calyceal puncture in partial staghorn and staghorn stone patients was sufficient in 72.2% of the antegrade group and in 78.9% of the retrograde group ( p=0.69). The double-puncture technique was necessary for 71.9% of renal pelvis stones in the antegrade group and for 9.4% in the retrograde group ( p<0.001). The antegrade approach reduced the mean operative time and analgesic requirement significantly ( p<0.001). No statistically significant difference, however, was found between the two groups regarding stone migration to the ureter, radiation time and postoperative complications. The stone-directed antegrade approach using the ‘bull’s eye’ technique is a safe and accurate method in PCNL access in patients with radiopaque and semi-opaque renal stones.